Proper ventilation permits firefighters to find and attack fires by releasing heat and smoke from confined spaces. It also inhibits smoke explosions and flashovers. The poor positioning of ventilation equipment can move either too much or too little air in a confined space. In the case of too little air movement, vision is obscured and the risk of inhaling poisonous gases is increased.
Increasing air flow, on the other hand, can cause a fire to grow and spread.
“Tactical ventilation” is a recent innovation in firefighting. Tactical ventilation involves any action used to move air to gain an advantage while fighting a fire in a confined space. For example, tactical ventilation draws fire away from the occupants of a confined space. Tactical ventilation also limits smoke, heat, and water damage. Tactical ventilation improves safety, conserves property, and reduces the time needed to put out a fire.
Tactical ventilation often involves the use of special fans, known as smoke ejectors, for drawing smoke and heat from confined spaces. When using smoke ejectors, it is necessary to have exits for the smoke (usually doors or windows) and to ensure that the exits remain open by wedging or propping. To save time, smoke ejectors are often set by firefighters in the bottom of an exit, on the floor for example, impeding the flow of air and limiting smoke ejector efficiency.